Presentation system and display device for use in the presentation system

ABSTRACT

A display device according synthesizes icons and messages with a portion where no descriptive display image is displayed by OSD for display. Icon functions are set by a PC so that the setting of the operation of the PC and the display device, and the setting of an external device can be conducted. The number of lines of the message to be displayed is determined according to distortion correction at the case of oblique projection to correct position coordinates detected by a camera. In a presentation system including an interactive white board device, the display device (for example, a liquid crystal projector), and the PC, the display of the icons are improved to extend the functions, and the display of the messages at the case of oblique projection, and a position detection precision on a screen by the camera incorporated into the display device are improved.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority from Japanese Patent ApplicationJP2009-248977, filed on Oct. 29, 2009, the content of which is herebyincorporated by reference into this application.

BACKGROUND OF THE INVENTION

The present invention relates to a presentation system, and a displaydevice for use in the presentation system, and more particularly to apresentation system that improves display of icons and messages, and adisplay device for the presentation system.

In a presentation system used for demonstration in rollout, reduction insize and weight and reduction in projector distance has been advanced toimprove the usability of a user. In particular, because a person(hereinafter referred to as “presenter”) who conducts presentationrequires a system that facilitates description, a technique by which theposition of an electrical pen (also called “pointer”) to be used israpidly and precisely detected is important.

JP-A-2003-276399 discloses a technique in which there are provided ascreen having a light permeability, an electrical pen that emits a lighthaving a predetermined wavelength while traveling on the screen, and aninfrared camera that receives the light that has been emitted from theelectrical pen and transmitted to a back side of the screen to detectthe position of the electrical pen to precisely detect the position ofthe electrical pen on an interactive white board.

SUMMARY OF THE INVENTION

For the purpose of providing an interactive white board system that isimproved in usability for not only the presenter but also a person towhom the presentation is given (hereinafter referred to as “presentationparticipant”), it is conceivable that, for example, icon or messagedisplay on the interactive white board needs to be further devised.

The interactive white board is provided with an interface for allowingthe presenter to conduct, on the interactive white board, the operationof paging up a presentation document, or switching over the displayedcolor or size of a line traced with an electrical pen, for example. Thisremoves the burden that the presenter directly operates a PC (personcomputer) connected with the interactive white board and controlling thedisplay.

As the conventional interface, there is an example in which icons areprinted directly on the interactive white board. Also, there is anexample in which the PC side is provided with a display applicationincluding the icons, and displayed on the interactive white boardtogether with a descriptive display image.

When the presenter touches the icon on the interactive white board withthe electrical pen, position coordinate detection sensors incorporatedinto the interactive white board read designated position information,and transmit the position information to the connected PC. Theapplication on the PC that has received the position informationidentifies the function of PC operation associated with the icon whichis located at the position coordinates, and executes the function. Withthis operation, the operation of paging up the presentation document andso on as described above is conducted.

As a method of detecting the operation of the presenter, there areposition coordinate detection sensors of the type in which theelectrical pen uses a pressure generated when the electrical pen touchesthe interactive white board. Also, unless the electrical pen directlytouches the interactive white board, the position of the electrical pencan be detected by allowing electromagnetic waves such as infrared raysto be emitted from the electrical pen, and then received by theinteractive white board. Also, the position coordinate detection sensorsare arranged on the interactive white board with high precision so as todetect the position with precision of every pixel or every severalpixels of a display screen. For example, the sensors are arranged with ahigh density so as to detect the position over the entire surface of theinteractive white board with high precision. For that reason, thepresenter can write on the display screen described above with the pen.

However, in the above-mentioned method, some matters to be furtherimproved are indicated. First, when the icons are printed directly onthe interactive white board, naturally, the display position of theicons cannot be changed over, and a new function cannot be added, or thefunction cannot be extended. Even when the display application includingthe icons is provided at the PC side, because the function and displayposition of the icons are fixed conventionally, the same problem arises.Because the icons that are the interface for the PC operation areconfigured as described above, the icons are superimposed on thedescriptive display image up to now, and prevent the presentationparticipant from visually recognizing the descriptive display image.Also, the presenter must be moved from the standing position foroperating the icons depending on the position at which the presenterstands. Thus, the icons prevent the presentation from proceedingsmoothly. In addition, there is a proposal to display messages at thesame location instead of the display of the icons. However, problemsoccurring in association with this proposal have not been sufficientlyconsidered.

The present invention has been made in view of the above circumstances,and therefore an object of the present invention is to provide apresentation system that improves the display of icons and messages, anda display device for the presentation system.

In order to achieve the above object, according to the presentinvention, there is provided a presentation system including: aninteractive white board device having a display section for an image; adisplay device that optically emits an image to the interactive whiteboard device to display the image; and a system control device thatstores a presentation image which is supplied to the display device, andcontrols the operation of the display device, wherein the display deviceincludes an OSD display control section that generates an icon displayimage on the basis of control information supplied from the systemcontrol device, and an OSD synthesis processing section that synthesizesthe presentation image supplied from the system control device with theicon display image generated by the OSD display control section withoutsuperimposition with each other to generate a display image to bedisplayed on the interactive white board.

Also, according to the present invention, there is provided apresentation system including: an interactive white board device havinga display section for an image; a display device that optically emits animage to the interactive white board device to display the image; and asystem control device that stores a presentation image which is suppliedto the display device, and controls the operation of the display device,wherein the display device includes an OSD display control section thatgenerates a message display image on the basis of control informationsupplied from the system control device, and an OSD synthesis processingsection that synthesizes the presentation image supplied from the systemcontrol device with the message display image generated by the OSDdisplay control section without superimposition with each other togenerate a display image to be displayed on the interactive white board.

Further, according to the present invention, there is provided a displaydevice for use in a presentation system, which optically emits an imageto an interactive white board device having a display section of theimage for displaying the image, the display device including: a displaydevice control section that controls the operation of the displaydevice; an image processing section that reduces a first image input tothe display device in a vertical direction to generate a second image onthe basis of a command related to a projection angle to the interactivewhite board from the display device control section; an OSD displaycontrol section that generates a third image which is displayed togetherwith the second image on the basis of a command from the display devicecontrol section; an OSD synthesis processing section that synthesizesthe second image and the third image without superimposition with eachother to generate a fourth image; a distortion correction processingsection that reduces the fourth image in a horizontal directionaccording to a vertical position of the fourth image on the basis of thecommand related to the projection angle to the interactive white boardfrom the display device control section to generate a fifth image; andan optical display section that optically emits the fifth image to theinteractive white board, wherein the display device control sectioncontrols the OSD display control section so as to reduce the third imagein the vertical direction according to the reduction processing of thefirst image in the vertical direction in the image processing section.

According to the present invention, there can be provided thepresentation system that improves the display of the icons and themessages, and the display device for use in the presentation system,which can contribute to an improvement in the usability for a user.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, objects and advantages of the presentinvention will become more apparent from the following description whentaken in conjunction with the accompanying drawings wherein:

FIG. 1 is a block diagram illustrating a presentation system accordingto an embodiment of the present invention;

FIG. 2 is a block diagram illustrating a conventional presentationsystem;

FIG. 3 is a block diagram illustrating another presentation systemaccording to the embodiment of the present invention;

FIG. 4 is a block diagram illustrating still another presentation systemaccording to the embodiment of the present invention;

FIG. 5 is a diagram illustrating one example of a display methodaccording to the embodiment of the present invention;

FIG. 6 is a diagram illustrating another example of a display methodaccording to the embodiment of the present invention;

FIG. 7 is a diagram illustrating a relationship between distortioncorrection and OSD display according to the embodiment of the presentinvention;

FIG. 8 is a diagram illustrating a relationship between the distortioncorrection and the OSD display according to the embodiment of thepresent invention;

FIG. 9 is a diagram illustrating one example of a PC application screenaccording to the embodiment of the present invention;

FIG. 10 is a diagram illustrating a format of icon information accordingto the embodiment of the present invention;

FIG. 11 is a block diagram illustrating a display device according tothe embodiment of the present invention;

FIG. 12 is a block diagram illustrating an OSD display section of adisplay device according to the embodiment of the present invention;

FIG. 13 is a block diagram illustrating another display device accordingto the embodiment of the present invention; and

FIG. 14 is a diagram for explaining differences in vision according tothe embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of the present invention will be described withreference to the accompanying drawings.

FIG. 1 is a block diagram illustrating a presentation system accordingto an embodiment of the present invention. The presentation systemincludes an interactive white board device 1, a display device 2 using,for example, a liquid crystal projector, and a PC (also called “systemcontrol device”) 3 that controls the entire system. The interactivewhite board device 1 and the PC 3 are connected to each other through acommunication cable 40 such as a USB (universal serial bus). With theuse of this communication cable 40, the interactive white board device 1transmits information including position coordinate detectioninformation of an electrical pen described above to the PC 3. Thedisplay device 2 and the PC 3 are connected to each other through animage cable 41, and the PC 3 transmits an information signal for displayto the display device 2. A communication cable 42 is also used toconnect the display device 2 and the PC 3 on the basis of the standardsof, for example, RS-232C (recommended standard-232C) and an LAN (localarea network). The PC 3 controls the operation of the display device 2.The display device 2 optically transmits a display image to theinteractive white board device 1, and displays the display image on adisplay section thereof.

A display section 101 of the interactive white board device 1 includes adisplay section 102 of a descriptive display image, and a displaysection 103 of, for example, icons. The display of the display section102 and the display of the display section 103 are synthesized by usingan OSD (on screen display) function provided to the display device 2 aswill be described later. In this example, the display section 103 isarranged on a left end side of the screen. In the display section 102 isdisplayed an image shown in a display 31 provided to the PC 3 as shownin FIG. 1. The image is supplied from the PC 3 to the display device 2through the above-mentioned image cable 41.

As described above, position coordinate detection sensors 110 detect aposition indicated by an electrical pen (not shown) with precision ofevery pixel or every several pixels of the display section 101, andtransmit position information to the PC 3 through the communicationcable 40. The position coordinate detection sensors 110 are located inthe upper left of the interactive white board device 1, and soconfigured as to detect the position coordinates of the entire screen inFIG. 1. Alternatively, the position coordinate detection sensors 110 maybe configured to be located on the substantially entire surface of thedisplay section 101 with high density.

In the display section 103 are displayed icons 111. In the PC 3 arestored plural bit map files so that the respective icons 111 displaydifferent images. A presenter operates the PC 3 before presentation soas to set a display position of each icon 111 and the presence orabsence of the display in advance. The display position of the icons 111is set on the basis of the position information provided in the positioncoordinate detection sensors 110. Information for generating the icons111 shown in the display section 103 is set by the PC 3 and registeredin an internal memory, together with the bit map files and theinformation on the display position. The information is further suppliedfrom the PC 3 to the display device 2 through the above-mentionedcommunication cable 42.

When the presenter points at any one of the icons 111 with theelectrical pen, the position coordinate detection sensors 110 detect thepointed position, for example, by the aid of a pressure or anelectromagnetic wave. When the detected position information istransmitted to the PC 3, the PC 3 knows which icon has been selected,and starts, for example, application associated with the selected icon.When the selected icon is related to the operation of the PC 3, theapplication controls the PC 3. When the selected icon is related to theoperation of the display device 2, the application transmits a controlcommand to the display device 2 through the communication cable 42.

The image displayed in the display section 102 and the image displayedin the display section 103 are synthesized in an OSD synthesis sectionincluded in the display device 2 on the basis of a control from the PC3, and displayed in the display section 101.

FIG. 2 is a block diagram of a conventional presentation system. Afterdescription of the conventional example with reference to FIG. 2, thefeatures of the present invention will be described by comparing FIG. 1with FIG. 2.

In FIG. 2, components that can be identical with those in FIG. 1 aredenoted by the same symbols. Icons 112 are located, for example, at theleft end side of the screen in the interactive white board device 1 byprinting. The display device 2 can display the descriptive display imagewhile avoiding the left end side. However, because the position of theicons 112 is fixed, the descriptive display image may be superimposed onthe icons 112 according to the setting status. Also, there is a case inwhich the PC 3 allows an icon group 300 to be located inside the displaysection 102, and transmits the display image to the display device 2.The icons 112 are fixed, and the display position and the presence orabsence of the display cannot be switched. Further, although the icongroup 300 can have the display position moved within a region of thedisplay section 102, because the icon group 300 is superimposed on thedescriptive display image, the icon group 300 prevents the vision of thedisplay image by a presentation participant.

This embodiment shown in FIG. 1 has the following features as comparedwith the case of FIG. 2. First, the bit map files of the icons to bedisplayed and the display position data in the interactive white boarddevice 1 are transmitted from the application provided in the PC 3 tothe display device 2 through the communication cable 42 and storedtherein. Further, with the use of the OSD display function of thedisplay device 2, the icon bit maps are displayed in the display section103 which is not superimposed on the display section 102 of thedescriptive display image on the basis of the display position data.

Also, the display section 103 is defined as follows. For example, whenthe aspect ratio (a ratio of the lateral length to the vertical length)of the display section 101 in FIG. 1 is 16:9 as with a wide NTSCtelevision, and the aspect ratio of the descriptive display image in thedisplay section 102 is 4:3 (12:9) as with a standard NTSC television, ablank space occurs in the lateral direction of the display section 101.FIG. 1 shows a case in which the display device 2 moves the blank spaceto the left end side of the display section 101 according to aninstruction from the PC 3, and the display section 103 is located anddisplayed in the blank space. It is needless to say that the blank spacecan be moved to the right end side according to an instruction from thePC 3. Also, it is possible that the blank spaces are located in both ofthe left end side and the right end side, and the display section 102 ismoved to the central portion of the display section 101 for display.

For that reason, unlike the case of FIG. 2, in this embodiment, theicons 111 are not superimposed on the image displayed in the displaysection 102, and do not prevent the presentation participant fromviewing the image. Because the presence or absence of the display ofeach icon can be instructed from the PC 3, the present status can bepreset to a status in which icons unnecessary in description by thepresenter are eliminated. Further, the presenter can preset the locationof the display section 103 of the icons to any one of the left end sideand the right end side by the aid of the PC 3, according to whether theinteractive white board 1 is located at the right side or the left side,or whether the presenter is right-handed or left-handed. As a result,the presenter moves the position for conducting the icon operation,thereby enabling the problem that the smooth progress of presentation isprevented to be eliminated.

The case in which the display section 103 of the icons is located withthe use of the aspect ratio of the display section 101 and thedescriptive display image was described. However, the present inventionis not limited to this embodiment. The image can be reduced anddisplayed within a problem-free region to use a resultant blank space.Also, the display section 103 of the icons is not limited to the leftend side or the right end side, but may be located at the upper end sideor the lower end side. Even in the display section 102 of thedescriptive display image, an image portion having no characterinformation, or no fine information, such as sky or a puddle is detectedso that the icons can be located in that image portion. In this case,there can be provided a function of automatically discriminating aportion suitable for the provision of the icons. As a result, the iconsdo not prevent the presentation participant from viewing the images.

FIG. 3 is a block diagram of another presentation system according tothe embodiment of the present invention. FIG. 3 shows a case in whichthe display sections 103 of the icons are located at both of the leftend side and the right end side of the display section 101 as comparedwith FIG. 1. As described above, this arrangement can be implemented bygiving an instruction on the display method to the display device 2 fromthe PC 3. For example, functions related to the operation of the PC 3 aswill be described later can be arranged at the left end side, andfunctions related to the display device 2 can be arranged at the rightend side so that the presenter can easily find any icon according to thefunctions.

In the above description, the interactive white board 1 is exemplifiedas a device that displays the image. However, the technique of thisembodiment can be also implemented by a device having an LCD (liquidcrystal display) or a PDP (plasma display panel) as the display section.As the position coordinate detection sensor for the electrical pen, asensor that detects a pressure or an electromagnetic wave can beapplied, likewise.

Similarly, the icons 111 of FIG. 1 can be associated with not only thefunction related to the operation of the PC 3 but also the function forallowing the presenter to operate the display device 2. For example,because the interest of the presenter participant is concentrated on thepresenter when description using the displayed drawing has beenterminated once, the drawing may be erased once. In this situation, afunction for turning off an illumination optical system of the displaydevice 2 including the liquid crystal projector, or blocking a light tothe interactive white board device 1 corresponds to the latter function.

Further, because the icons 111 has the function not fixed as in theconventional art, the function of the icons 111 can be further extendedby extending the application of the PC 3. For example, when a reproducedmoving picture is supplied from a video player (not shown) to thedisplay device 2, an icon for selecting any one of the reproduced movingpicture and an image supplied from the PC 3 is newly provided. As aresult, a system in which the PC 3 controls the display device 2 so asto selectively display the image to be displayed on the interactivewhite board device 1 can be realized, thereby enabling the effect of thepresentation to be further enhanced.

Subsequently, still another embodiment of the present invention will bedescribed with reference to FIGS. 4 to 6. FIG. 4 is a block diagram ofstill another presentation system according to the embodiment of thepresent invention. In this example, unlike FIG. 1, the display section103 functions as not the display area of the icons 111 but a stringdisplay area 120 for message display. The string display area 120 isused to display supplemental description in presentation which has beenprepared in advance, a formal name of abbreviation, or the like. Also,during presentation, the presenter or another operator can display amessage by operating the PC 3. Although the position coordinatedetection sensor 110 is omitted, the string display area 120 can beprovided in the system that can display the icons 111 as shown in FIG. 1by switching the display. When the PC 3 gives an instruction to theinteractive white board device 1, an unfixed message with arbitrarycontents can be displayed on the interactive white board device 1 asneeded. It is needless to say that the string display area 120 can belocated at not only the left end side of the display section 101 butalso the right end side, the upper end side or the lower end side. Also,the operator may select whether the string display area 120 is sodisplayed as to be superimposed on the display section 102 of thedescriptive display image, or not, by the PC 3. String data is, forexample, data input from a keyboard (not shown) of the PC 3 by theoperator, or data stored in a memory provided in the PC 3. The data issupplied to the display device 2 through the communication cable 42. Asoccasion demands, the display device 2 can store the string datasupplied from the PC 3 in a nonvolatile memory.

Incidentally, when the display device 2 such as a liquid crystalprojector displays a message, there arises a problem which will bedescribed with reference to FIGS. 5 and 6. FIG. 5 is a diagram forexplaining an example of a display method according to the embodiment ofthe present invention. FIG. 6 is a diagram for explaining anotherexample of a display method according to the embodiment of the presentinvention.

Taking the actual use state of the display device 2 such as the liquidcrystal projector into consideration, a manner of emitting a projectionlight from the direct front side of the interactive white board device 1is rarely used. It is general to emit the projection light from aposition at which the display device 2 is not impeditive when viewedfrom the presenter participant, for example, from the obliquely lowerside or the oblique upper side. A case in which the projection light isemitted from the center in the horizontal direction and the obliquelower side in the height direction with respect to the interactive whiteboard device 1 will be described.

In this case, the enlargement factor is more increased toward a portiondisplayed on the upper portion on the screen, and a distortion occurs inthe display image. Accordingly, the display device 2 frequently has sucha distortion correction function as to reduce the image displayed on theupper portion of the interactive white board device 1. In two images ofFIG. 5, an upper image is an image to be projected by the display device2 when the projection light is emitted from the direct front side inboth of the horizontal direction and the height direction with respectto the interactive white board device 1. A lower image is an image to beprojected by the display device 2 when the projection light is emittedfrom the oblique lower side only in the height direction. A broken lightin FIG. 5 indicates a display region 104 corresponding to the displayregion in the interactive white board device 1. That is, when theprojection light is emitted from the oblique lower side, an image signalis reduced toward the upper image in both of the vertical direction andthe horizontal direction of the screen in the display device 2. As aresult, the distortion can be corrected. After the image signal has beenfirst reduced in the vertical direction by reducing scanning lines,processing in the horizontal direction is conducted on the image signal.Then, the projection light is emitted from the direct front side of theinteractive white board device 1 to provide an image signal displayed ina trapezoidal shape as indicated by a lower image of FIG. 5. As aresult, the image signal can be displayed without any distortionoccurring in the entire surface of the display region 104. This can becalled “Keystone display”.

Incidentally, attention must be newly paid to the message display byreducing the image in the vertical direction as will be described later.In the display device 2, the above-mentioned processing in the verticaldirection is first conducted on the image that is displayed in thedisplay section 102. Thereafter, because the strings of a predeterminedsize are synthesized by OSD, the display section 103 becomes relativelylarger than the display section 102 in the vertical direction. For thatreason, in this embodiment, after the display section 102 has beendisplayed in the predetermined size, the number of lines of the stringswhich are displayed in the display section 103 is reduced. When asufficient message display cannot be conducted by reducing the strings,the strings can be displayed by scrolling in the vertical direction bythe display control section to read all of the strings everypredetermined time.

Unlike FIG. 5, FIG. 6 shows a case in which the electron zoom functionprovided in the display device 2 is effective. When the image isdisplayed in a state where the zoom ratio is high, an image signalreduced in both of the vertical direction and the horizontal directionis required in order to display the same angle of view as shown in alower side of FIG. 6, as compared with a case where the zoom ratio isstandard as shown in an upper side of FIG. 6.

In this case, in this embodiment, both of the number of strings that canbe displayed and the number of characters per line are reduced. Asmentioned above, when the sufficient message display cannot be executed,the strings can be displayed by scrolling in the vertical direction soas to display all of the strings every predetermined time.

The items described with reference to FIGS. 5 and 6 will be furtherdescribed with an example of the OSD display with reference to FIG. 7.FIG. 7 is a diagram showing a relationship between the distortioncorrection and the OSD display according to the embodiment of thepresent invention.

Referring to FIG. 7, reference symbol 600 a denotes an image that isdisplayed by the display device 2 from the direct front side of theinteractive white board device 1. In this example, OSD displayindicative of numeral is conducted in a portion corresponding to aheight a in the vertical direction. In the case where the image isdisplayed from the oblique lower side of the interactive white boarddevice 1, the above-mentioned distortion correction is executed, animage indicated by 600 b is provided in an output section of the displaydevice 2 to the interactive white board device 1 (corresponding to theimage in the liquid crystal panel, for example, in the liquid crystalprojector) is provided. That is, as will be described again later, afteran image reduced in the vertical direction has been generated by theimage processing section provided in the display device 2, the image issynthesized with the OSD image of a predetermined size (height a) by theOSD synthesis processing section, and the horizontal direction of thesynthetic image is then reduced according to a position in the verticaldirection by the distortion correction processing section.

When the image is displayed on the interactive white board device 1 fromthe oblique lower side by the display device 2, the relative enlargementfactor is obtained as indicated by a dashed line 601 in reference symbol600 c in FIG. 7. Therefore, the image can be viewed from thepresentation participant as indicated by reference symbol 600 d in FIG.7. That is, the image whose distortion has been corrected is obtained.However, when reference symbol 600 a and 600 d are compared with eachother, the height of the OSD display portion is obtained as indicated byreference symbol b in FIG. 7, which is longer than the original heighta.

The above items will be described with an example in which the OSDdisplay is conducted entirely in the vertical direction with referenceto FIG. 8. The same is applied to the above-mentioned message displayshown in FIG. 4. FIG. 8 is a specific diagram showing a relationshipbetween the distortion correction and the OSD display according to theembodiment of the present invention.

Referring to FIG. 8, reference symbol 602 a indicates an image that isdisplayed from the direct front side of the interactive white boarddevice 1 by the display device 2. In this example, the OSD displayindicative of numerical is conducted at the left end side of the screenentirely in the vertical direction. When the image is displayed from theoblique lower side of the interactive white board device 1, the image issubjected to the above-mentioned distortion correction, and the image isdisplayed on the interactive white board device 1 from the oblique lowerside by the display device 2, the relative enlargement factor isobtained as indicated by a dashed line 601 in reference symbol 602 b inFIG. 8. When the image is displayed on the interactive white boarddevice 1 as it is, the upper end portion of a numeral display portion inFIG. 8 gets out of the display region of the interactive white boarddevice 1. For that reason, the number of lines displayed is reduced bythe OSD display control section provided in the display device 2 so thatthe upper end falls within the display region, as indicated by referencesymbol 602 c in FIG. 8. When the number of lines to be displayed isshort, scroll display can be conducted as described above. Similarly, inthe embodiment where icons are displayed in the display section 103 ofFIGS. 1 and 3, it is conceivable that the distortion correction isconducted, and the icon portion gets out of the display region of theinteractive white board device 1. However, in this case, the displayintervals of the icons can be reduced by the OSD display control sectionprovided in the display device 2 so that the icon display falls withinthe display region.

Subsequently, returning to a case in which the icons are displayed inthe display section 103 as shown in FIGS. 1 and 3, the set screen of theicons to be displayed in the PC 3, and the setting method will bedescribed. FIG. 9 is a diagram showing one example of a PC applicationscreen according to the embodiment of the present invention. FIG. 9schematically shows an example of a PC application window 400 displayedon the display 31 provided in the PC 3 of FIG. 1. Examples differentfrom FIG. 9 in the arrangement on the screen and so on can be proposed,but those examples fall within the scope of this embodiment.

A model select list 401 within the PC application window 400 is made upof, for example, pull-down menus. A model list of the display device 2which can be controlled by the PC 3 is displayed by clicking an arrow atthe right end with a mouse (not shown). The user selects a desired modelfrom the list by clicking the model with the mouse. Then, a connectiontarget of the selected model is displayed in a connection target selectlist 402. In this example, an example in which a name of the connectiontarget and an IP address are displayed is shown. In this example, threemodels selected by the user are provided. Among those models, when adisplay device of the connection target “YYY” is used, the displaydevice is clicked with the mouse for selection. As a result, the PC 3starts transfer of information with respect to the display device 2selected by the user.

Then, the icons are set. An example in which 12 kinds of icons are setis shown. The user selects the arrangement of a desired icon through thepull-down menu of an icon display pattern select list 403. When apattern 1 is selected as shown in FIG. 9, the icons are so arranged asto be divided into the left end side and the right end side of theinteractive white board device 1. When a pattern 2 and the subsequentpatterns are selected, the icons are so arranged as to be concentratedon the left end side as shown in FIG. 1. When the icons are arranged atthe upper end side and the lower end side, the arrangement of the iconsaccording to a desire of the user can be selected.

In FIG. 9, in an icon display pattern 404 added with numerals of 1 to12, its function is determined by setting the function in a functionselect list 405. In this case, the function of the icon display pattern404 added with numerical of, for example, 1 is an icon for setting thesize of a pen in the function select list 405. In FIG. 9, the functionselect list 405 with numerals of 1 to 12 has pull-down menus, and fromthose menus, the user selects the function of the icon display pattern404. For example, the function of the icon display pattern 404 withnumeral of 1 can be changed to an icon for setting the color of the pen.When the bit map files for displaying the respective functions and iconscorrespond one-to-one with each other, the icon display is also changedat the same time. In the function select list 405 shown in the figureare shown a large number of functions related to the control of the PC3. However, the function related to the display device 2 such as ON/OFFfunction of display can be included in the function select list 405.

When the function is not set to the icon display pattern with numeralof, for example, 12, a portion written as, for example, “nothing” isselected from the pull-down menu in the function select list withnumeral of 12 in the figure. In this situation, no icon is displayed inthe subject display section of the interactive white board device 1.Also, the same icon display pattern is set in plural places, and theicons that are frequently used can be arranged, for example, on both ofthe left end side and the right end side of the interactive white boarddevice 1 to improve the usability of the presenter.

The above display pattern can be set during presentation, but is usuallypreset in advance. After the display pattern has been completed, when atransmit button 406 is clicked, information related to the select,arrangement and the functions of the icon are transmitted to the displaydevice 2 from the PC 3, and then stored in a memory provided in thedisplay device 2. When an edit button 407 is clicked, a new function canbe added to the function select list 405, or the bit map patterns of theicons can be edited.

Subsequently, the structure of the information related to the select,arrangement and functions of the icons which are transmitted to thedisplay device 2 from the PC 3 will be described with reference to FIG.10. FIG. 10 is a diagram showing a format of the icon informationaccording to the embodiment of the present invention.

Referring to FIG. 10, reference numeral 1001 indicates display positionof the respective icons in the interactive white board device 1. Anexample in which the display positions are divided in the verticaldirection and the horizontal direction for designation is shown.Although the number of bits is changed even according to the number ofscanning lines and the number of display pixels, the number of bits isso selected as to obtain the position information with a predeterminedprecision. Because each icon has a predetermined size, if theinformation on the display position has a precision for each pixel, theicon can be displayed in a predetermined region around the designatedposition, or in a predetermined region with the designated position setas, for example, the left upper end. The identification of an icon whenthe electrical pen points at the icon as described above can beconducted with the use of the position information in the same manner.

Reference numeral 1002 denotes Nos. added with the bit map files of thesubject icons. For example, when the types of bit map files are 256 orlower, the number of bits may be 8 bits. Reference numeral 1003 denotesinformation on an encoded icon function corresponding to the selectedicon. When the user sets the functions of the respective icons by theaid of the function select list 405 shown in FIG. 9, the bit maps andfunctions of the icons in the respective display positions 1001 are set.

Reference numeral 1004 denotes information indicative of whether thereis the icon display in the interactive white board device 1, or not. Forexample, when the icons are set so as not to be displayed in a specificplace in the function select list 405 as described above, thisinformation announces this fact. When an agreement is made in advance soas not to display the icons in the case where no instruction is given tothe icon function 1003, the display presence/absence 1004 may beunnecessary.

As described above, when the information shown in FIG. 10 is transmittedto the display device 2 from the PC 3, the display of the icons in theinteractive white board device 1 can be controlled.

Subsequently, the configuration of the display device 2 will bedescribed with reference to FIG. 11. FIG. 11 is a block diagram of thedisplay device according to the embodiment of the present invention. Inthis example, a case in which the Keystone display described withreference to FIG. 5 is conducted will be described.

Referring to FIG. 11, an input terminal 200 is connected with the imagecable 41 of FIG. 1, and an information signal of the descriptive displayimage which is supplied by the PC 3 is input to the display device 2.The input signal is received by an input processing section 201, andoutput to an image processing section. A part of processing for theKeystone display described above with reference to FIG. 5 is conductedin the image processing section 202. Processing of reducing the numberof scanning lines or the like is conducted as a part of processing thatexecutes distortion correction to reduce the vertical direction,according to an instruction from a control section (also called “displaydevice control section”) 203 including a CPU (central processing unit).The control section 203 executes the above-mentioned instruction basedon the projection angle with respect to the interactive white boarddevice 1. The image processing section 202 also converts the aspectratio, the zoom ratio, and the number of display pixels as occasiondemands, according to an instruction from the control section 203. Anoutput signal of the image processing section 202 is input to one end ofan OSD synthesis processing section 207, and subjected to OSD synthesisas will be described later.

Subsequently, a signal that is input to the other end of the OSDsynthesis processing section 207 will be described.

An input/output terminal 211 is connected with the communication cable42 of FIG. 1, and a command for control is transferred between the PC 3and the display device 2. The information related to the icon displaydescribed above with reference to FIGS. 9 and 10 is also suppliedtogether with the control command. The information related to the icondisplay is divided by the communication processing section 212 andsupplied to the control section 203. The information is further suppliedto an OSD display control section 206 through the control section 203.An OS (operating system) and application of the control section 203 arestored in a ROM 204, and the running information of the control section203 is temporarily stored in the RAM 205.

In the OSD display control section 206, the icons or the message imagesto be synthesized with the above-mentioned image in the OSD synthesissection 207, on the basis of information on the bit maps or the displayposition of the icons which has been supplied through the controlsection 203, or on the basis of character fonts that have been suppliedfrom a built-in font ROM, are supplied to the above-mentioned other endof the OSD synthesis section 207.

The image signal that has been synthesized in the OSD synthesis section207 is subjected to the other parts of processing for conducting thedistortion correction by the distortion correction processing section208. That is, the horizontal direction is reduced according to theposition in the vertical direction, and converted into an image signalwhich is displayed in a trapezoidal shape when the projection light isemitted from the direct front side of the interactive white board device1 as shown in FIG. 5. The degree of reduction is determined according toan instruction from the control section 203.

After an output signal of the distortion correction processing section208 has been amplified in power until a liquid crystal panel 210 can besufficiently driven by a panel drive control section 209, the outputsignal controls the permeability of the liquid crystal panel 210. Aswell known, the liquid crystal panel 210 is disposed for each of threeprimary color signals of RGB. Also, a projection light is supplied tothe liquid crystal panel 210 from an illumination optical system notshown. The three primary color lights of RGB that have transmitted theliquid crystal panels 210 are emitted to the interactive white boarddevice 1 through a lens group forming a projection optical system notshown to display an image.

The configuration of the OSD display control section 206 shown in FIG.11 will be described with reference to FIG. 12. FIG. 12 is a blockdiagram showing an OSD display section of the display device accordingto the embodiment of the present invention. A case in which messagedisplay strings are generated on the basis of a control from the PC 3will be described.

To an OSD control section 230 provided in the OSD display controlsection 206 is input information related to characters which aredisplayed from the above-mentioned control section 203. The informationis input as binary code data 234 supplied from the PC 3 as shown in thefigure. The binary code data 234 includes data representingcorresponding characters and data representing the display position. TheOSD control section 230 is connected with a font ROM 233. The font ROM233 has a correspondence table 235 of the respective binary codes andcharacters. Referring to the font ROM 233, the OSD control section 230replaces the respective input binary codes with character bit maps 236,and stores the bit maps 235 in a RAM 232. For example, when the binarycode is 4Eh, the OSD control section 230 stores the bit map of thecharacter N therein. Thereafter, referring to the bit maps 236 stored inthe RAM 232, the OSD control section 230 renders the image in a placecorresponding to the display position of the OSD frame memory 231. Anexample of the rendered results is indicated by reference numeral 237 inFIG. 12. Data that has been stored in the OSD frame memory 231 issupplied to the other end of the above-mentioned OSD synthesisprocessing section 207 through the OSD control section 230. In thissituation, the OSD control section 230 determines the number of lines indisplaying the image on the interactive white board device 1, or alsodetermines the number of characters per line in zoom display, forexample, on the basis of information on the projection angle to theinteractive white board device 1. The OSD control section 230 conductsthe scroll display as described above as occasion demands. When the icondisplay shown in FIG. 1 is conducted, information related to the bit mapfiles of the icons is supplied from the PC 3 to the display device 2,stored in the RAM 232, and rendered in the OSD frame memory 231.

Subsequently, an example in which the determination of the icon pointedby the electrical pen is conducted by the aid of not the positioncoordinate detection sensor 110, but an image pickup section (camera)provided in the display device 2 will be described with reference toFIG. 13. FIG. 13 is a block diagram of another display device accordingto the embodiment of the present invention. Unlike the case of FIG. 11,a camera 220 and an image recognition processing section 221 are newlyprovided, and the image recognition processing section 221 transferscontrol information with respect to the control section 203. Also, whenthe icon pointed by the electrical pen is related to the function of thePC 3, the control section 203 transmits detected information to the PC 3through the communication processing section 212 and the input/outputterminal 211.

The camera 220 points to the interactive white board device 1 thatdisplays the image projected by the display device 2. When the presenterpoints at the icon with the electrical pen, the icon at which the imagerecognition processing section 221 has pointed is detected, and informedthe control section 203 to on the basis of the image detected by thecamera 220. Incidentally, the presenter participant who views the imagedisplayed on the interactive white board device 1 from the direct frontposition can see the image looking like the rectangular image shown inthe upper half of FIG. 5, as the trapezoidal image shown in the lowerhalf of FIG. 5 when the image is viewed from the position of the displaydevice 2 that emits the light from the front and oblique lower side. Forthat reason, more improvement is required to precisely detect the iconthat has been pointed by the electrical pen from the image detected bythe camera 220.

In this embodiment, the image recognition processing section 221 obtainsthe original position of the icon detected by the camera 220 on thebasis of the information of the projection angle to the interactivewhite board device 1 which is supplied from the control section 203 toprecisely detect the icon. Also, for example, corners (for example, fourcorners) of the display image are pointed by the electrical pen beforepresentation, this image is detected by the camera 220, and the positioninformation is informed the control section 203 to through the imagerecognition processing section 221. During the subsequent presentation,the positions of the respective icons which have been detected by thecamera 220 are corrected on the basis of the position information toprecisely detect the icons.

This item will be described in more detail with reference to FIG. 14.FIG. 14 is a diagram for explaining differences in vision according tothe embodiment of the present invention.

First, reference symbol 500 a in FIG. 14 shows a case in which thedisplay device 2 projects the image from the direct front side to theinteractive white board device 1. In this case, not only the presenterparticipant but also the camera 220 incorporated into the display device2 can view a rectangular image with no distortion. This case suffersfrom no problem.

Reference symbol 500 b shows a case in which the display device 2projects the image from the oblique lower side to the interactive whiteboard device 1, and the presenter participant views the image. The imageis not subjected to the distortion correction as described above. Theenlargement factor becomes larger toward the upper side of the image,and the image is viewed as an inverted trapezoidal image. When the sameimage is viewed at the position of the camera 220 incorporated into thedisplay device 2, the image is viewed as the same rectangular image asthat of 500 a as shown by reference symbol 500 c. Because the camera 220travels integrally with the display device 2, the camera 220 is held inparallel to the optical axis so that the image is viewed as therectangular image.

On the other hand, in the case where the image has been subjected to thedistortion correction, converted into an image shown by reference symbol500 d, and projected, the image is viewed as a trapezoidal image shownby reference numeral 500 d when the image is viewed at the position ofthe camera 220 incorporated into the display device 2. The image isviewed by the presenter participant as a rectangular image with nodistortion as shown by reference symbol 500 e.

A state of reference symbol 500 d is shown again as reference numeral500 f in the lower portion of the figure. It is assumed that thepresenter points at the position of reference numeral 501 in the figure,when viewed from the camera 220. The position of reference numeral 501is located at the upper portion of the image. When viewed at the angleof view of the camera 220 indicated by a broken line in the figure, anerror occurs because the camera 220 detects the position as a positioncloser to the center from the real position. Under the circumstances,before presentation, four corners of the image indicated by referencenumeral 502 are pointed by the electrical pen, and the positioninformation detected by the camera 220 is stored, compared with correctposition information, and corrected to precisely detect the position. Asa result, as shown by reference numeral 500 g, the positions of the fourcorners are precisely detected to positions indicated by referencenumeral 503. It is found by conducting proportional calculationcorresponding to the positions in the vertical direction and thehorizontal direction at the same ratio that the above-mentioned positionindicated by reference numeral 501 is precisely a position indicated byreference numeral 504. Thus, the correct position can be detected. Thisprocess can be implemented by conducting arithmetic operation in theimage recognition processing section 220 provided in the display device2.

As has been described above, in this embodiment, the display positionsof the icons can be switched according to the desire of the user. Theicons to be displayed can be chosen, and a new function can be loaded.The icons are not superimposed on the image used for presentation, anddo not visually interrupt the image. Not only the operation of the PCbut also the operation of the display device such as the liquid crystalprojector can be conducted by the aid of the icons. When the image isprojected from a position other than the direct front side, the numberof lines of messages to be displayed can be optimally selected even ifdistortion is corrected. Also, the correct detection can be conductedeven when the position is detected by the camera incorporated into thedisplay device.

The above embodiment is exemplified and does not limit the presentinvention. Different embodiments are proposed on the basis of thesubject matter of the present invention, but those embodiments do notdepart from the scope of the present invention.

While we have shown and described several embodiments in accordance withour invention, it should be understood that disclosed embodiments aresusceptible of changes and modifications without departing from thescope of the invention. Therefore, we do not intend to be bound by thedetails shown and described herein but intend to cover all such changesand modifications that fall within the ambit of the appended claims.

What is claimed is:
 1. A display device for use in a presentationsystem, which optically emits an image to an interactive white boarddevice having a display section of the image for displaying the image,the display device comprising: a display device control sectioncomprising a central processing unit, the display device control sectioncontrols the operation of the display device; an image processingsection that reduces a first image input to the display device in avertical direction to generate a second image on the basis of a commandrelated to a projection angle to the interactive white board from thedisplay device control section; an OSD display control section thatgenerates a third image which is displayed together with the secondimage on the basis of a command from the display device control section;an OSD synthesis processing section that synthesizes the second imageand the third image without superimposition with each other to generatea fourth image; a distortion correction processing section that reducesthe fourth image in a horizontal direction according to a verticalposition of the fourth image on the basis of the command related to theprojection angle to the interactive white board from the display devicecontrol section to generate a fifth image; and an optical displaysection that optically emits the fifth image to the interactive whiteboard, wherein the display device control section controls the OSDdisplay control section so as to generate the third image to modify itsdisplay form in the vertical direction according to the reductionprocessing of the first image in the vertical direction in the imageprocessing section by reducing a number of scanning lines, to synthesizethe second image that is the inputted image of which width in thevertical direction is reduced and the third image that is an OSD imageafter both images are generated separately, and to reduce thesynthesized image in the horizontal direction according to theprojection angle and to correct the distortion.
 2. The display devicefor use in a presentation system according to claim 1, wherein when thethird image is a character message display image, the display devicecontrol section controls the OSD display control section so as to reducethe number of scanning lines in the vertical direction of the charactermessage.
 3. The display device for use in a presentation systemaccording to claim 1, wherein when the third image is an icon displayimage, the display device control section controls the OSD displaycontrol section so as to reduce intervals in the vertical directionbetween icons of the icon display image.
 4. The display device for usein a presentation system according to claim 1, further comprising: animage pickup section that picks up a fifth image displayed on theinteractive white board device disposed along an optical axial directionof the optical display section, wherein the third image generated by theOSD display control section includes an icon corresponding to a functionfor setting the function of a device including a device connected to theexternal of the display device, and wherein the display device controlsection generates, when a user of the display device for use in thepresentation system indicates a specific position of the interactivewhite board device, the position coordinate information on the specificposition on the basis of the fifth image picked up by the image pickupsection.
 5. The display device for use in a presentation systemaccording to claim 4, wherein the display device control sectioncorrects an error of the position coordinate information accompanied bythe reduction processing in the image processing section and thereduction processing.
 6. The display device for use in a presentationsystem according to claim 5, wherein the display device control sectioncorrects the error of the position coordinate information on the basisof the position coordinate information on a corner of the image in thefifth image picked up by the image pickup section.